This paper provides the first in-depth study of clitic doubling in vernacular Medieval Greek. First, it is shown that the four-part typology (topicalization; right-dislocation; backgrounding; left-dislocation) recently developed on the basis of Modern Greek is perfectly applicable to vernacular Medieval Greek. Moreover, clitic doubling serves the same pragmatic function in Medieval Greek as in many modern spoken languages: it marks an object as the topic of the utterance (as opposed to the focus). For this purpose, the notion of ‘topic’ is clearly defined and distinguished from the concept of (referential) ‘givenness’. Special attention is paid to the distribution of the clitic pronouns, as their position is diagnostic for the topic/focus distinction. Innovatively, the frequent occurrence of clitic doubling in my corpus is associated with the oral discourse which the vernacular texts are acknowledged to adopt. In this regard, two other constructions are discussed: dislocated genitives and dislocated subjects.